From: Ankur Arora ankur.a.arora@oracle.com
Replace mentions of PREEMPT_AUTO with PREEMPT_LAZY.
Also, since PREMPT_LAZY implies PREEMPTION, we can reduce the TASKS_RCU selection criteria from this:
NEED_TASKS_RCU && (PREEMPTION || PREEMPT_AUTO)
to this:
NEED_TASKS_RCU && PREEMPTION
CC: Paul E. McKenney paulmck@kernel.org Reviewed-by: Frederic Weisbecker frederic@kernel.org Reviewed-by: Sebastian Andrzej Siewior bigeasy@linutronix.de Signed-off-by: Ankur Arora ankur.a.arora@oracle.com Signed-off-by: Paul E. McKenney paulmck@kernel.org Signed-off-by: Boqun Feng boqun.feng@gmail.com --- include/linux/srcutiny.h | 2 +- kernel/rcu/Kconfig | 2 +- kernel/rcu/srcutiny.c | 14 +++++++------- 3 files changed, 9 insertions(+), 9 deletions(-)
diff --git a/include/linux/srcutiny.h b/include/linux/srcutiny.h index 1321da803274..31b59b4be2a7 100644 --- a/include/linux/srcutiny.h +++ b/include/linux/srcutiny.h @@ -64,7 +64,7 @@ static inline int __srcu_read_lock(struct srcu_struct *ssp) { int idx;
- preempt_disable(); // Needed for PREEMPT_AUTO + preempt_disable(); // Needed for PREEMPT_LAZY idx = ((READ_ONCE(ssp->srcu_idx) + 1) & 0x2) >> 1; WRITE_ONCE(ssp->srcu_lock_nesting[idx], READ_ONCE(ssp->srcu_lock_nesting[idx]) + 1); preempt_enable(); diff --git a/kernel/rcu/Kconfig b/kernel/rcu/Kconfig index b9b6bc55185d..e2206f3a070c 100644 --- a/kernel/rcu/Kconfig +++ b/kernel/rcu/Kconfig @@ -91,7 +91,7 @@ config NEED_TASKS_RCU
config TASKS_RCU bool - default NEED_TASKS_RCU && (PREEMPTION || PREEMPT_AUTO) + default NEED_TASKS_RCU && PREEMPTION select IRQ_WORK
config FORCE_TASKS_RUDE_RCU diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c index 4dcbf8aa80ff..f688bdad293e 100644 --- a/kernel/rcu/srcutiny.c +++ b/kernel/rcu/srcutiny.c @@ -98,7 +98,7 @@ void __srcu_read_unlock(struct srcu_struct *ssp, int idx) { int newval;
- preempt_disable(); // Needed for PREEMPT_AUTO + preempt_disable(); // Needed for PREEMPT_LAZY newval = READ_ONCE(ssp->srcu_lock_nesting[idx]) - 1; WRITE_ONCE(ssp->srcu_lock_nesting[idx], newval); preempt_enable(); @@ -120,7 +120,7 @@ void srcu_drive_gp(struct work_struct *wp) struct srcu_struct *ssp;
ssp = container_of(wp, struct srcu_struct, srcu_work); - preempt_disable(); // Needed for PREEMPT_AUTO + preempt_disable(); // Needed for PREEMPT_LAZY if (ssp->srcu_gp_running || ULONG_CMP_GE(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max))) { preempt_enable(); return; /* Already running or nothing to do. */ @@ -138,7 +138,7 @@ void srcu_drive_gp(struct work_struct *wp) WRITE_ONCE(ssp->srcu_gp_waiting, true); /* srcu_read_unlock() wakes! */ preempt_enable(); swait_event_exclusive(ssp->srcu_wq, !READ_ONCE(ssp->srcu_lock_nesting[idx])); - preempt_disable(); // Needed for PREEMPT_AUTO + preempt_disable(); // Needed for PREEMPT_LAZY WRITE_ONCE(ssp->srcu_gp_waiting, false); /* srcu_read_unlock() cheap. */ WRITE_ONCE(ssp->srcu_idx, ssp->srcu_idx + 1); preempt_enable(); @@ -159,7 +159,7 @@ void srcu_drive_gp(struct work_struct *wp) * at interrupt level, but the ->srcu_gp_running checks will * straighten that out. */ - preempt_disable(); // Needed for PREEMPT_AUTO + preempt_disable(); // Needed for PREEMPT_LAZY WRITE_ONCE(ssp->srcu_gp_running, false); idx = ULONG_CMP_LT(ssp->srcu_idx, READ_ONCE(ssp->srcu_idx_max)); preempt_enable(); @@ -172,7 +172,7 @@ static void srcu_gp_start_if_needed(struct srcu_struct *ssp) { unsigned long cookie;
- preempt_disable(); // Needed for PREEMPT_AUTO + preempt_disable(); // Needed for PREEMPT_LAZY cookie = get_state_synchronize_srcu(ssp); if (ULONG_CMP_GE(READ_ONCE(ssp->srcu_idx_max), cookie)) { preempt_enable(); @@ -199,7 +199,7 @@ void call_srcu(struct srcu_struct *ssp, struct rcu_head *rhp,
rhp->func = func; rhp->next = NULL; - preempt_disable(); // Needed for PREEMPT_AUTO + preempt_disable(); // Needed for PREEMPT_LAZY local_irq_save(flags); *ssp->srcu_cb_tail = rhp; ssp->srcu_cb_tail = &rhp->next; @@ -261,7 +261,7 @@ unsigned long start_poll_synchronize_srcu(struct srcu_struct *ssp) { unsigned long ret;
- preempt_disable(); // Needed for PREEMPT_AUTO + preempt_disable(); // Needed for PREEMPT_LAZY ret = get_state_synchronize_srcu(ssp); srcu_gp_start_if_needed(ssp); preempt_enable();